Generationanddistributionofawide-bandcontinuouslytunablemillimeter-wavesignalwithanopticalexternalmodulationtechnique教程.pdfVIP

3090 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 53, NO. 10, OCTOBER 2005 Generation and Distribution of a Wide-Band Continuously Tunable Millimeter-Wave Signal With an Optical External Modulation Technique Guohua Qi, Jianping Yao, Senior Member, IEEE, Joe Seregelyi, Stéphane Paquet, and Claude Bélisle Abstract—A new technique to generate and distribute a wide- Therefore, the highest frequency of the signal produced by band continuously tunable millimeter-wave signal using an optical these DSB techniques is limited by the bandwidth of the laser external modulator and a wavelength-fixed optical notch filter is or the external modulator and the fiber chromatic dispersion. To proposed. The optical intensity modulator is biased to suppress the odd-order optical sidebands. The wavelength-fixed optical notch overcome these limitations, an optical generation scheme that filter is then used to filter out the optical carrier. Two second-order uses narrow bandwidth optical components to generate high- optical sidebands are obtained at the output of the notch filter. A frequency electrical signals becomes attractive. millimeter-wave signal that has four times the frequency of the Optical microwave or millimeter-wave signal generation is microwave drive signal is generated by beating the two second- usually based on heterodyne techniques by beating two optical order optical sidebands at a photodetector. Since no tunable op- tical filter is used, the system is easy to implement. A system using carriers separated by the desired frequency in a square-law pho- an LiNbO3 intensity modulator and a fiber Bragg grating filter todetector (PD). If the offset frequency of the two optical car- is built. A stable and high spectral purity mi